How can I recover a deleted tax return?

OK.... I finished my 22 Tax Return....  I could not file as one form from IRS needed to be updated.  Today I got a note that the form was ready to download.  I up[dated as directed.  When the computer returned to my tax form... My Tax Form Was Erased..... I'd have to re enter everything again!!!!  I've searched the computer for my form.  ZIP.  I had used the CD form to enter my taxes.  AND none of the turbo tax downloads would open my taxes.  They all begin at step ONE......  HELP:

I purchased the Business Home disc version from the store. I completed one tax but had not transmitted it but I did save as to an external hard I then started my second tax and stopped before completing it but I saved it as well. When I went back to complete them about 30 minutes had passed and I went to open the second tax everything was fine but when I opened the first tax it had the tax information belonging   to the second tax.

How do I get the first tax backreturn.